About Arc Flash

Arc flash risk are a serious concern. Be informed about how your company can avoid an arc flash accident. Contact us with any questions.

Arc flash introduction

The electric industry is becoming increasingly aware of a phenomenon known as arc flash, a short circuit that passes through air between two live conductors, or between a live conductor and ground. This short circuit can be accompanied by incredible amounts of heat and pressure, and the results are often deadly. The frequency of reported incidents is on the increase, prompting increased awareness and action in the electric and safety industries.

What can cause arch flash to occur?

Arc flash can be caused from something as simple as approaching a high amperage source with a conductive object. Poorly maintained equipment or sub-standard parts may also trigger an arc flash. Missing insulation, corrosion or impurities on conductors may also cause arc flash to occur.

What injuries can result?

Arc flash injuries are almost always extremely severe. Intense heat, up to 35k degrees F, can cause fatal burns even when the victim is up to 5 feet away from the source. Serious burns can still occur at up to 10 feet. With such extreme heat, metal can vaporize, causing additional hazards from molten droplets which can be propelled by the force of the flash. Finally, high intensity flashes can cause permanent eye damage resulting in blindness.

Is arc flash a common problem?

Arc flash has only begun to receive significant industry attention in recent years. Before arc flash was understood, it was believed that electrical shock was the primary cause of all injuries in an electrical accident. While electrical shock does cause burns, the majority of all hospital admissions due to electrical accident related injuries were from arc flash. Industry professionals estimate that at least 5 to 10 arc flash explosions occur per day in the U.S., resulting in approximately 1 to 2 deaths daily.

What about arc blast?

High energy faults can produce immense pressure and sound waves. This is known as an arc blast, and may accompany an arc flash accident. The pressure from such a blast can be hit a victim with as much as 2000 lb/sqft of pressure. This is enough pressure to propel metal objects at several hundred miles per hour, or even knock down walls.

What standards are in place?

NFPA 70E

"This standard addresses those electrical safety requirements for employee workplaces that are necessary for the practical safeguarding of employees?" This standard contains vital information to avoiding accidents involving arc flash, including information on proper hazard identification through compliant labeling.

More information is available from:
http://www.nfpa.org/aboutthecodes/AboutTheCodes.asp?DocNum=70E

National Electric Code (2005/2008)

The NEC, also known as NFPA 70, contains vital information on proper electrical installations, including information on properly marking hazards. The 2008 revision includes information on labeling compliance and arc flash hazards.

More information is available from:
http://www.nfpa.org/aboutthecodes/AboutTheCodes.asp?DocNum=70